who is supposed to call _initialize of an adapted reactor module?

[yamt]

i have a preview1 reactor module, which exports _initialize.
when adapting it with wasi_snapshot_preview1.reactor.wasm and loading the resulted component with wasmtime,
i expected the _initialize export of the original module is somehow called during the component startup.
however, it doesn't seem to be called.

[alexcrichton]

Currently the *.reactor.wasm adapter doesn't do anything with _initialize, so you'll likely want to build your own adapter which calls it as part of the start function or implicitly as part of exports.

Alternatively a convention could be built into wit-component to perhaps do this automatically but that would be pretty complicated implementation-wise since it would need to handle the fact that _initialize is optional.

[yamt]

Currently the *.reactor.wasm adapter doesn't do anything with _initialize, so you'll likely want to build your own adapter which calls it as part of the start function or implicitly as part of exports.

ok.
i put a hack in the (non-standard) entry point of my module and it's working well.

Alternatively a convention could be built into wit-component to perhaps do this automatically but that would be pretty complicated implementation-wise since it would need to handle the fact that _initialize is optional.

i guess it's necessary for a reactor built with wasi-libc to work correctly.

[alexcrichton]

Most of the usage of _initialize in wasi-libc for example has been pushed to lazy instead of eager initialization, which if possible is what I would recommend for other uses as well. Otherwise feel free to open an issue on the wasm-tools repository for a proposal about how to add _initialize support to wit-component and adapters of course!